Production method of electrically conductive graphene composite fiber

ABSTRACT

A graphene composite fiber includes graphene sheets and a polymer for aggregating the graphene sheets together. The polymer includes either or both of a hyperbranched polymer and polyvinyl alcohol. The graphene sheets and the polymer are stacked on each other to form a layered structure, and the graphene sheets are regularly arranged along an axial direction of the graphene composite fiber. In a production method of the graphene composite fiber, a graphene oxide is used as a raw material, which significantly improves tensile strength of the graphene composite fiber. Addition of the polymer provides good tenacity for the composite fiber. In a spinning process, rotated coagulant is used to increase a tensile force of a gelatinous fiber, so that the gelatinous fiber has high orientation and tacticity, thereby significantly improving strength of an obtained solid fiber. The final reduction process restores electrical conductivity of a graphene fairly well.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2014/072689, filed on Mar. 3, 2014, which claims priority toChinese Patent Application No. 201310332049.2, filed on Aug. 1, 2013,both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a composite fiber material, and inparticular to an electrically conductive graphene composite fiber and aproduction method thereof.

BACKGROUND

A carbon fiber is a new material with excellent performance, which hasnot only an intrinsic property of a carbon material, but also flexibleprocess ability of a textile fiber. Compared with a traditional glassfiber, the Young's modulus of the carbon fiber is more than 3 times thatof the traditional glass fiber; compared with a Kevlar fiber (KF-49),not only the Young's modulus of the carbon fiber is approximately 2times that of the Kevlar fiber, but also the carbon fiber has notableperformance such as corrosion resistance and tensile strength.Therefore, the carbon fiber is widely used in the civil use, military,construction, chemical, industry, aerospace, and supercar fields.

Graphene is a two-dimensional layer of carbon atoms linked by means ofsp2 hybridization, and has many excellent properties such as ultrahighstrength, extremely large specific surface area, high thermalconductivity and carrier mobility, and therefore has a broad applicationprospect in many fields such as transistors, super capacitors,selectively permeable membranes, and enhanced materials. If theultrahigh strength of a single graphene sheet can be transferred to amacroscopic material, the strength of the single graphene sheet in themacroscopic material is comparable to that of the carbon fiber. Researchfinds that, by using a wet spinning technique, a liquid crystallinesolution of a graphene oxide can be converted into a macroscopicgraphene fiber. However, the strength of the obtained graphene fiber isapproximately 100 to 200 MPa, which is still much lower than thestrength of the single graphene sheet. The obtained graphene fiber canmeet practical application requirements only when its strength andelectrical conductivity are further improved.

SUMMARY

An objective of the present invention is to provide a production methodof an electrically conductive graphene composite fiber having highstrength and electrical conductivity.

A graphene composite fiber includes graphene sheets and a polymer foraggregating the graphene sheets together, where the polymer includeseither or both of a hyperbranched polymer and polyvinyl alcohol, thegraphene sheets and the polymer are stacked on each other to form alayered structure, and the graphene sheets are regularly arranged alongan axial direction of the graphene composite fiber.

A production method of an electrically conductive graphene compositefiber includes: step 1, adding 1 part by weight of a graphene oxide, 50to 2000 parts by weight of a solvent, and 0.1 to 100 parts by weight ofa polymer to a reactor, and stirring, so as to obtain nanocompositematerial spinning slurry of the polymer and graphene, where the polymerincludes either or both of a hyperbranched polymer and polyvinylalcohol; step 2, extruding the spinning slurry through a spinning nozzlewith a diameter of 5 to 5000 μm at a rate of 1 to 100 mL/h, retainingthe spinning slurry in rotated coagulant for 1 to 3600 s to coagulatethe spinning slurry into fibers; and step 3, washing the coagulatedfiber product, drying the coagulated fiber product in a vacuum, and thenperforming reduction to obtain the graphene composite fiber.

Strength of the graphene composite fiber mainly depends on interactionsbetween graphene sheets. For a fiber formed by graphene sheets, thereare mainly Van der Waals force and π-πinteractions between the graphenesheets. However, a polymer having a large number of functional groupsexists between the graphene sheets in this embodiment, and the polymerand hydroxyl and carboxyl groups in the graphene sheets form hydrogenbonds or ionic bonds, which act like glue to “bond” adjacent graphenesheets together, thereby increasing the strength and electricalconductivity of the graphene composite fiber.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a digital camera photo of a graphene composite fiber woundaround a roller of polytetrafluoroethylene according to an embodiment ofthe present invention;

FIG. 2 is a partial SEM image of a graphene composite fiber wound arounda roller of polytetrafluoroethylene according to an embodiment of thepresent invention; and

FIG. 3 is a cross-sectional SEM image of the graphene composite fiberaccording to an embodiment of the present invention in FIG. 2.

DESCRIPTION OF EMBODIMENTS Embodiment 1

As shown in FIG. 1 to FIG. 3, a graphene composite fiber provided by anembodiment of the present invention includes graphene sheets and apolymer for aggregating the graphene sheets together. The graphenesheets and the polymer are closely stacked to form a layered structure,and the graphene sheets are regularly arranged along an axial directionof the graphene composite fiber. The polymer includes either or both ofa hyperbranched polymer and polyvinyl alcohol. The graphene compositefiber is a black fiber having a diameter of 5 to 5000 μm.

Particularly, as shown in FIG. 2, the graphene sheets 1 in the fiber areall arranged along the axial direction of the fiber, and therefore havea very high tacticity. Particularly, as shown in FIG. 3, the graphenesheets 1 and the added polymer are closely stacked to form a layeredstructure, laying a basis for high strength of the graphene sheets.

The hyperbranched polymer includes one or more of hyperbranchedpolyester, a hyperbranched polyamide, and hyperbranched polyglycidylether.

Strength of the graphene composite fiber in this embodiment of thepresent invention mainly depends on interactions between graphene sheets1. For a fiber formed by graphene sheets 1 alone, there are mainly Vander Waals force and π-πinteractions between the graphene sheets.However, in this embodiment, a polymer having a large number offunctional groups is introduced into the graphene sheets, and thepolymer and hydroxyl and carboxyl groups in the graphene sheets 1 formhydrogen bonds or ionic bonds, which act like glue to “bond” adjacentgraphene sheets 1 together, thereby increasing the strength of thegraphene composite fiber.

Embodiment 2

This embodiment of the present invention provides a production method ofan electrically conductive graphene composite fiber, including:

Step 1: Add 1 part by weight of a graphene oxide, 50 to 2000 parts byweight of a solvent, and 0.1 to 100 parts by weight of a polymer to areactor, and stir, so as to obtain a nanocomposite material spinningslurry of the polymer and graphene, where the polymer includes either orboth of a hyperbranched polymer and polyvinyl alcohol.

Step 2: Extrude the spinning slurry through a spinning nozzle with adiameter of 5 to 5000 μm at a rate of 1 to 100 mL/h, and retain thespinning slurry in rotated coagulant for 1 to 3600 s to coagulate thespinning slurry into fibers.

Step 3: Wash the coagulated fiber product, dry the coagulated fiberproduct in a vacuum, and then perform reduction to obtain the graphenecomposite fiber.

A diameter of the electrically conductive graphene composite fiberranges from 5 pm to 5000 μm.

The hyperbranched polymer includes one or more of hyperbranchedpolyester, a hyperbranched polyamide, and hyperbranched polyglycidylether.

The solvent in step 1 includes one or more of N-methyl-2-pyrolidone,N,N-dimethylformamide, and water.

The coagulant in step 2 includes one or more of a NaOH aqueous solution,a KOH aqueous solution, a CaCl2 aqueous solution, a NaOH methanolsolution, a KOH methanol solution, a CaCl2 methanol solution, a NaOHethanol solution, a KOH ethanol solution, a CaCl2 ethanol solution,diethyl ether, ethyl acetate, acetone, and petroleum ether.

A reduction method in step 3 includes thermal reduction and chemicalreduction. A reducing agent used in the chemical reduction includes oneor more of hydrazine hydrate, vitamin C, lysine, potassium hydroxide,sodium hydroxide, hydroiodic acid, and acetic acid.

The production method of the graphene composite fiber in this embodimentof the present invention may include the following specificimplementation manners

1. In another embodiment of the present invention, the foregoing stepsmay be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 20 mg of the graphene oxide, 1 g of anN-methyl-2-pyrolidone solvent, and 2 g of hyperbranched polyester to thereactor, and stirring for 1 hour, so as to obtain a nanocompositematerial spinning slurry of the hyperbranched polyester and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyester and graphene through a spinning nozzle with adiameter of 5000 μm at a rate of 1 mL/h, and retaining the nanocompositematerial spinning slurry in a rotated KOH methanol solution for 50 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 40 degrees for 24 hours, and then performing reduction byusing hydrazine hydrate, so as to obtain a composite fiber of thehyperbranched polyester and graphene, where the composite fiber has adiameter of 5000 μm, a breaking strength of 400 MPa, a breakingelongation of 5%, and an electrical conductivity of 200 S/m.

2. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 20 mg of the graphene oxide, 0.5 g of anN-methyl-2-pyrolidone solvent, and 2 mg of a hyperbranched polyamide tothe reactor, and stirring for 4 hours, so as to obtain a nanocompositematerial spinning slurry of the hyperbranched polyamide and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyamide and graphene through a spinning nozzle with adiameter of 5 μm at a rate of 100 mL/h, and retaining the nanocompositematerial spinning slurry in a rotated NaOH methanol solution for 5 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 60 degrees for 24 hours, and then performing reduction byusing vitamin C, so as to obtain a composite fiber of the hyperbranchedpolyamide and graphene, where the composite fiber has a diameter of 5μm, a breaking strength of 450 MPa, a breaking elongation of 10%, and anelectrical conductivity of 2000 S/m.

3. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 20 mg of the graphene oxide, 40 g of anN,N-dimethylformamide solvent, and 100 mg of hyperbranched polyglycidylether to the reactor, and stirring for 6 hours, so as to obtain ananocomposite material spinning slurry of the hyperbranched polyglycidylether and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyglycidyl ether and graphene through a spinning nozzlewith a diameter of 100 μm at a rate of 10 mL/h, and retaining thenanocomposite material spinning slurry in rotated diethyl ether for 3600s to coagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 60 degrees for 24 hours, and then performing reduction byusing vitamin C and lysine, so as to obtain a composite fiber of thehyperbranched polyglycidyl ether and graphene, where the composite fiberhas a diameter of 100 μm, a breaking strength of 500 MPa, a breakingelongation of 15%, and an electrical conductivity of 3000 S/m.

4. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 20 mg of the graphene oxide, 10 g of anN,N-dimethylformamide solvent, and 200 mg of polyvinyl alcohol to thereactor, and stirring for 24 hours, so as to obtain a nanocompositematerial spinning slurry of the polyvinyl alcohol and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thepolyvinyl alcohol and graphene through a spinning nozzle with a diameterof 50 μm at a rate of 20 mL/h, and retaining the nanocomposite materialspinning slurry in rotated acetone for 360 s to coagulate thenanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 60 degrees for 24 hours, and then performing reduction byusing hydroiodic acid, so as to obtain a composite fiber of thepolyvinyl alcohol and graphene, where the composite fiber has a diameterof 50 μm, a breaking strength of 550 MPa, a breaking elongation of 8%,and an electrical conductivity of 3500 S/m.

5. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 20 mg of the graphene oxide, 10 g of awater solvent, and 200 mg of a hyperbranched polyamide to the reactor,and stirring for 3 hours, so as to obtain a nanocomposite materialspinning slurry of the hyperbranched polyamide and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyamide and graphene through a spinning nozzle with adiameter of 800 μm at a rate of 1 mL/h, and retaining the nanocompositematerial spinning slurry in a rotated CaCl2 aqueous solution for 1 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing reduction byusing acetic acid, so as to obtain a composite fiber of thehyperbranched polyamide and graphene, where the composite fiber has adiameter of 800 μm, a breaking strength of 450 MPa, a breakingelongation of 5%, and an electrical conductivity of 1000 S/m.

6. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 10 mg of the graphene oxide, 10 g of awater solvent water, and 200 mg of a hyperbranched polyamide to thereactor, and stirring for 24 hours, so as to obtain a nanocompositematerial spinning slurry of the hyperbranched polyamide and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyamide and graphene through a spinning nozzle with adiameter of 5000 μm at a rate of 1 mL/h, and retaining the nanocompositematerial spinning slurry in a rotated CaCl2 ethanol solution for 50 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing reduction byusing a mixture of hydroiodic acid and acetic acid, so as to obtain acomposite fiber of the hyperbranched polyamide and graphene, where thecomposite fiber has a diameter of 5000 μm, a breaking strength of 515MPa, a breaking elongation of 5%, and an electrical conductivity of 5000S/m.

7. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 10 mg of the graphene oxide, 10 g of anN,N-dimethylformamide solvent, and 200 mg of hyperbranched polyester tothe reactor, and stirring for 10 hours, so as to obtain a nanocompositematerial spinning slurry of the hyperbranched polyester and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyester and graphene through a spinning nozzle with adiameter of 5000 μm at a rate of 1 mL/h, and retaining the nanocompositematerial spinning slurry in rotated ethyl acetate for 50 s to coagulatethe nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing reduction byusing KOH, so as to obtain a composite fiber of the hyperbranchedpolyester and graphene, where the composite fiber has a diameter of 5000μm, a breaking strength of 545 MPa, a breaking elongation of 5%, and anelectrical conductivity of 4500 S/m.

8. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 10 mg of the graphene oxide, 10 g of anN,N-dimethylformamide solvent, and 200 mg of a hyperbranched polyamideto the reactor, and stirring for 10 hours, so as to obtain ananocomposite material spinning slurry of the hyperbranched polyamideand graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyamide and graphene through a spinning nozzle with adiameter of 100 μm at a rate of 10 mL/h, and retaining the nanocompositematerial spinning slurry in rotated petroleum ether for 50 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing reduction byusing NaOH, so as to obtain a composite fiber of the hyperbranchedpolyamide and graphene, where the composite fiber has a diameter of 100μm, a breaking strength of 460 MPa, a breaking elongation of 5%, and anelectrical conductivity of 1200 S/m.

9. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 10 mg of the graphene oxide, 10 g of anN-methyl-2-pyrolidone solvent, and 200 mg of hyperbranched polyester tothe reactor, and stirring for 5 hours, so as to obtain a nanocompositematerial spinning slurry of the hyperbranched polyester and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thehyperbranched polyester and graphene through a spinning nozzle with adiameter of 50 μm at a rate of 5 mL/h, and retaining the nanocompositematerial spinning slurry in rotated petroleum ether for 50 s tocoagulate the nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing thermal reductionat 500 degrees, so as to obtain a composite fiber of the hyperbranchedpolyester and graphene, where the composite fiber has a diameter of 50μm, a breaking strength of 525 MPa, a breaking elongation of 5%, and anelectrical conductivity of 2100 S/m.

10. In yet another embodiment of the present invention, the foregoingsteps may be specifically:

In the foregoing step 1, the adding 1 part by weight of a grapheneoxide, 50 to 2000 parts by weight of a solvent, and 0.1 to 100 parts byweight of a polymer to a reactor, and stirring, so as to obtain ananocomposite material spinning slurry of the polymer and graphene,specifically includes: adding 10 mg of the graphene oxide, 10 g of anN-methyl-2-pyrolidone solvent, and 200 mg of polyvinyl alcohol to thereactor, and stirring for 20 hours, so as to obtain a nanocompositematerial spinning slurry of the polyvinyl alcohol and graphene.

In the foregoing step 2, the extruding the spinning slurry through aspinning nozzle with a diameter of 5 to 5000 μm at a rate of 1 to 100mL/h, and retaining the spinning slurry in rotated coagulant for 1 to3600 s to coagulate the spinning slurry into fibers, specificallyincludes: extruding the nanocomposite material spinning slurry of thepolyvinyl alcohol and graphene through a spinning nozzle with a diameterof 5 μm at a rate of 15 mL/h, and retaining the nanocomposite materialspinning slurry in a rotated KOH ethanol solution for 50 s to coagulatethe nanocomposite material spinning slurry into fibers.

In the foregoing step 3, the washing the coagulated fiber product,drying the coagulated fiber product in a vacuum, and then performingreduction to obtain the graphene composite fiber, specifically includes:collecting the coagulated fiber product by using a winder, washing thecoagulated fiber product, drying the coagulated fiber product in avacuum at 80 degrees for 24 hours, and then performing reduction byusing acetic acid, so as to obtain a composite fiber of the polyvinylalcohol and graphene, where the composite fiber has a diameter of 5 μm,a breaking strength of 520 MPa, a breaking elongation of 5%, and anelectrical conductivity of 1300 S/m.

The spinning nozzle in the foregoing specific implementation mannersincludes spinning capillaries.

In the embodiments of the present invention, large graphene oxide sheetsare used as raw materials, which significantly improve tensile strengthof a graphene composite fiber. Addition of a polymer provides goodtenacity for the composite fiber. In a spinning process, tedious stepssuch as aeration, heating, reaction, centrifugation, and washing areremoved, so that a process is significantly simplified, and is easy tooperate, energy saving, and environment friendly. In the spinningprocess, rotated coagulant is used to increase a tensile force of agelatinous fiber, so that the gelatinous fiber has high orientation andtacticity, thereby significantly improving strength of an obtained solidfiber. The final reduction process restores electrical conductivity of agraphene fairly well, so that an obtained fiber has an electricalconductivity comparable to that of graphene paper (which is amacroscopic material formed by means of suction filtration of a graphenesolution, and is similar to paper in form). The graphene composite fiberobtained in the embodiments of the present invention has advantages ofhigh strength, good tenacity, and high electrical conductivity, may beproduced on a large scale, and may be widely used in the fields ofelectrically conductive fabrics, reinforcement of materials,electrically conductive devices, and the like.

The foregoing specifically describes the present invention by using theembodiments. The embodiments are merely intended to further describe thepresent invention, and should not be construed as a limitation on theprotection scope of the present invention. Unessential changes andadjustments made by a person skilled in the art according to content ofthe present invention shall fall within the protection scope of thepresent invention.

What is claimed is:
 1. A graphene composite fiber, comprising: graphenesheets; and a polymer for aggregating the graphene sheets together,wherein the polymer comprises at least one of a hyperbranched polymerand polyvinyl alcohol, the graphene sheets and the polymer areinterleaved and stacked to form a layered structure, and the graphenesheets are arranged along an axial direction of the graphene compositefiber.
 2. The graphene composite fiber according to claim 1, wherein thehyperbranched polymer comprises one or more of hyperbranched polyester,a hyperbranched polyamide, and hyperbranched polyglycidyl ether.
 3. Thegraphene composite fiber according to claim 1, wherein the polymercomprises one or two of hyperbranched polyester, a hyperbranchedpolyamide, hyperbranched polyglycidyl ether, and the polyvinyl alcohol.4. The graphene composite fiber according to claim 1, wherein thegraphene composite fiber has a diameter of 5 to 5000 μm.
 5. A productionmethod of an electrically conductive graphene composite fiber, themethod comprising: adding 1 part by weight of a graphene oxide, 50 to2000 parts by weight of a solvent, and 0.1 to 100 parts by weight of apolymer to a reactor, and stirring, so as to obtain a nanocompositematerial spinning slurry of the polymer and graphene, wherein thepolymer comprises at least one of a hyperbranched polymer and polyvinylalcohol; extruding the spinning slurry through a spinning nozzle with adiameter of 5 to 5000 pm at a rate of 1 to 100 mL/h, retaining thespinning slurry in rotated coagulant for 1 to 3600 s, to coagulate thespinning slurry into fibers; and washing the coagulated fibers, dryingthe coagulated fibers in a vacuum, and then performing reduction toobtain the graphene composite fiber.
 6. The production method of anelectrically conductive graphene composite fiber according to claim 5,wherein the polymer comprises one or two of hyperbranched polyester, ahyperbranched polyamide, hyperbranched polyglycidyl ether, and thepolyvinyl alcohol.
 7. The production method of an electricallyconductive graphene composite fiber according to claim 6, wherein thesolvent of 50 to 2000 parts by weight comprises one or more ofN-methyl-2-pyrolidone, N,N-dimethylformamide, and water.
 8. Theproduction method of an electrically conductive graphene composite fiberaccording to claim 6, wherein the coagulant comprises one or more of aNaOH aqueous solution, a KOH aqueous solution, a CaCl2 aqueous solution,a NaOH methanol solution, a KOH methanol solution, a CaCl2 methanolsolution, a NaOH ethanol solution, a KOH ethanol solution, a CaCl2ethanol solution, diethyl ether, ethyl acetate, acetone, and petroleumether.
 9. The production method of an electrically conductive graphenecomposite fiber according to claim 6, wherein the reduction methodcomprises thermal reduction or chemical reduction, wherein a reducingagent used in the chemical reduction comprises one or more of hydrazinehydrate, vitamin C, lysine, potassium hydroxide, sodium hydroxide,hydroiodic acid, and acetic acid.
 10. The production method of anelectrically conductive graphene composite fiber according to claim 5,wherein the spinning nozzle comprises spinning capillaries.